Gidday Au drivers,
One suggestion would be to also check if your Harmonic balancer is aligned as this can cause the slightest vibration appearing as missfire especially on idling and not so much on load. Just a thought from my AU3 SR petrol sedan.
I changed my spark plugs, coil pack, leads, renewed intake manifold as was leaking then slight vibration continued but noticed slight wobbly harmonic balancer and serpentine belt. Renewed and now purrs at idle with no previous vibration.
